For those not aware, Moloco (who normally do cars 1960's to 1980's) is going to release a UP prototype box car that just falls within the scope of this list (up to 1960). The car is a UP BC-50-5 class combination door 50' box car and also a BC-50-6 (built 1960).

Details at this link:- https://www.molocotrains.com/collections/freight-cars/products/res75051-omaha-50-combo-15-2-boxcar-bc-50-5-be-specific-delivery-scheme-1959

https://www.molocotrains.com/collections/freight-cars/products/res75069-omaha-50-combo-15-2-boxcar-bc-50-5-be-specific-delivery-scheme-1960

Robert Bogie